The present invention relates to an electronic system for remotely controlling locomotives in a train. The system is particularly suitable for use in transfer assignments as well as switching yard assignments.
Economic constraints have led railway companies to develop portable units allowing a ground-based operator to remotely control a locomotive in a switching yard. The module is essentially a transmitter communicating with a trail controller on the locomotive by way of a radio link. Typically, the operator carries this module and can perform duties such as coupling, and uncoupling cars while remaining in control of the locomotive movement at all times. This allows for placing the point of control at the point of movement thereby potentially enhancing safety, accuracy and efficiency.
Remote locomotive controllers currently used in the industry are relatively simple devices that enable the operator to manually regulate the throttle and brake in order to accelerate, decelerate and/or maintain a desired speed. The operator is required to judge the speed of the locomotive and modulate the throttle and/or brake levers to control the movement of the locomotive. Therefore, the operator must possess a good understanding of the track dynamics, the braking characteristics of the train, etc. to remotely operate the locomotive in a safe manner.
In several situations where locomotives and trains are used, there are both forward and backward movements of the train. In certain circumstances, the locomotive is pulling the train. In instances where the train is going in the opposite direction, the locomotive is pushing the train. In these situations, the remote locomotive controllers also enable the operator to manually regulate the direction of movement of the locomotive. Regulations define a limited distance during which the locomotive may push the train given that, during the time that the locomotive is pushing the train, there is no conductor at the front end of the train. A common solution to this problem is to have a caboose at the other end of the train where another conductor stands and observes where the train is going. Such a solution requires a duplication of the amount of personnel that is required to operate a train, thereby incurring additional costs in the form of an extra crew person. However, these extra crewmembers are required for security purposes.
Accordingly, there exists a need in the industry to provide a system for remotely controlling a locomotive that alleviates at least some of the problems associated with prior art devices.
In accordance with a broad aspect, the present invention provides a system of controller modules allowing to remotely control a train having a first locomotive and a second locomotive separated from one another by at least one car. The system of controller modules comprises a first controller module associated to the first locomotive and a second controller module associated to the second locomotive. One of the controller modules has a lead operational status and the other of the controller modules has a trail operational status. The controller module having the lead operational status includes an input for receiving a master control signal for signaling the train to move in a desired direction. The controller module having the lead operational status also includes an output to release in response to the master control signal a first local command signal operative to cause displacement of the locomotive associated with the controller module having the lead operational status. The controller module having the trail operational status includes an output. The controller module having a lead operational status is further operative to transmit to the controller module having a trail operational status a local control signal derived from the master control signal. The controller module having the trail operational status is responsive to the local control signal to generate a second command signal operative to cause displacement of the locomotive associated to the controller module having a trail operational status. The movement of the locomotive associated with the controller module having the lead operational status and the movement of the locomotive associated with the controller module having the trail operational status being such as to cause displacement of the train in the desired direction.
In a specific example of implementation, the first controller module is operative to acquire either one of a lead operational status and a trail operational status and the second controller module is operative to acquire either one of a lead operational status and a trail operational status. When one of said controller modules acquires the lead operational status the other of the controller modules acquires the trail operational status.
In a specific non-limiting example of implementation, the master control signal is an RF (a radio frequency) signal issued from a remote module. The master control signal carries information about the direction in which the train is to move and also information about the desired throttle and/or speed of the train.
The controller module having the lead operational status includes at the input a receiver unit that senses the master control signal, demodulates the master control signal to extract the information relating to the direction of movement and throttle, brake and/or speed of the train and passes this information to a processing unit. The processing unit generates the first local command signal that conveys a throttle setting information and a brake setting information. The first local command signal is applied to the locomotive associated to the controller module having the lead operational status such as to set the throttle at the desired setting and the brake at the desired setting in order to achieve the desired speed in the desired direction.
The processing unit also generates throttle setting information and brake setting information for the locomotive associated with the controller module having the trail operational status. Typically, the throttle setting information for the second locomotive is such as to produce a displacement of the locomotive associated to the controller module having the trail operational status having the same velocity and direction as the displacement of the locomotive associated with the controller module having the lead operational status. As for the brake setting information, it is essentially identical to the brake setting information for the first locomotive.
Alternatively, other control strategies may be implemented. For instance, differences are introduced between the throttle setting information and the brake setting information computed for the locomotive associated to the controller module having the lead operational status and the throttle setting information and the brake setting information computed for the locomotive associated to the controller module having the trail operational status. This may be desirable to better control the movement of the train and reduce train action for example. A specific example is a situation where the track dynamics, train length and/or weight may be such that a totally synchronized movement between the two locomotives is not desired.
The controller module having the lead operational status sends to the controller module having the trail operational status over an RF link, a local control signal that contains the throttle setting information and the brake setting information for the locomotive associated to the controller module having the trail operational status. The controller module having the trail operational status includes an input coupled to the receiver unit to establish the RF link with the controller module having the lead operational status. The receiver unit demodulates the local control signal and passes the extracted information to a processing unit that generates the second command signal for application to the locomotive associated with the controller module having the trail operational status such as to set the throttle and the brake of that locomotive.
It will be noted that under this specific non-limiting example of implementation, the receiver unit of the controller module having the lead operational status is used to communicate with the remote module (for receiving the master control signal) and also to establish the RF link with the controller module having the trail operational status. Accordingly, the receiver unit can communicate over at least two (and possibly more) separate communication links.
In the specific non-limiting example of implementation described above, the controller modules are operative to switch roles, in other words the lead operational status can be transferred from the first controller module to the second controller module. This is desirable in circumstances where the direction of movement of the train is changed. In particular, an advantageous practice is to assign the lead operational status to the locomotive that is pulling the train. Accordingly, when the controller module that currently holds the lead operational status receives a master control signal which indicates to relinquish its lead operational status, the controller module that currently holds the lead operational status relinquishes the lead operational status to the other controller module and acquires the trail operational status. The exchange of status is effected by an exchange of commands over the RF link between the two controller modules.
In a specific example, when the first controller module has the lead operational status and the second controller module has the trail operational status, the first controller module is operative to relinquish the lead operational status and acquire the trail operational status. Similarly, the second controller module is operative to relinquish the trail operational status and to acquire the lead operational status. When the second controller module acquires the lead operational status and when the first controller module acquires the trail operational status, the second controller module is operative to receive the master control signal and is operative to transmit to the first controller module a local control signal derived from the master control signal.
In accordance with another broad aspect, the invention provides a system for remotely controlling a train having a first locomotive and a second locomotive separated from one another by at least one car. The system comprises a first controller module associated to the first locomotive, a second controller module associated to the second locomotive and a remote control module. Each of the modules has a machine readable storage medium for storage of an identifier, the identifier allowing to uniquely distinguish the modules from one another. Each module is operative to transmit messages to another one of the modules over a non-proximity communication link. A message sent by any one of the modules over the non-proximity communication link is sensed by each of the other modules. Each message includes an address portion for holding the identifier of the module to which the message is directed. Each message may also include an identifier associated to the module from which the message was sent. The remote control module and the first controller module are operative to establish a first proximity data exchange transaction. During the first proximity data exchange transaction, the remote control module acquires and stores in the machine readable storage medium of the remote control module the identifier of the first controller module. Similarly, the first controller module acquires and stores in the machine readable storage medium of the first controller module the identifier of the remote control module. The first proximity data exchange transaction excludes the second controller module.
The remote control module and the second controller module are operative to establish a second proximity data exchange transaction. During the second proximity data exchange transaction, the remote control module acquires and stores in the machine readable storage medium of the remote control module the identifier of the second controller module. Similarly, the second controller module acquires and stores in the machine readable storage medium of the second controller module the identifier of the remote control module and the identifier of the first controller module. The second proximity data exchange transaction excludes the first controller module.
The first controller module and the second controller module are operative to establish a third data exchange transaction over the non-proximity communication link such that the first controller module acquires and stores in the machine readable storage medium of the first controller module the identifier of the second controller module.
In a specific example of implementation, the first controller module is operative to acquire either one of a lead operational status and a trail operational status and the second controller module is operative to acquire either one of a lead operational status and a trail operational status. When one of said controller modules acquires the lead operational status, the other of the controller modules acquires the trail operational status.
The remote control module generates a master control signal for signaling the train to move in a desired direction. The controller module having the lead operational status includes an input for receiving the master control signal and an output to generate in response to the master control signal a first local command signal operative to cause displacement of the locomotive with which it is associated. The controller module having the lead operational status is further operative to transmit to the controller module having the trail operational status a local control signal derived from the master control signal. The controller module having the trail operational status has an output and it is responsive to the local control signal to generate a second command signal operative to cause displacement of the second locomotive such as to cause displacement of the train in the desired direction.
In a specific example of implementation, the non-proximity communication link is a radio frequency (RF) link, the first and second proximity data exchange transactions are effected over respective infra red (IR) links. Alternatively, first and second proximity data exchange transactions are effected over links selected from the set consisting of an infra red link, a coaxial cable link, a wire link and an optical cable link.
For the purposes of this specification, the expression xe2x80x9cproximity data exchange transactionxe2x80x9d is used to designate a transaction over a communication link where the participants of the transaction receive the messages that are transmitted over the communication link. Examples of such communication links include an infra red link, a coaxial cable link, a wire link and an optical cable link.
For the purposes of this specification, the expression xe2x80x9cnon-proximity communication linkxe2x80x9d is used to designate a transaction over a communication link where components other that the participants of the transaction receive the messages that are transmitted over the communication link. Examples of such communication links include radio frequency links.